您当前所在位置: 首页 > 学者
在线提示

恭喜!关注成功

在线提示

确认取消关注该学者?

邀请同行关闭

只需输入对方姓名和电子邮箱,就可以邀请你的同行加入中国科技论文在线。

真实姓名:

电子邮件:

尊敬的

我诚挚的邀请你加入中国科技论文在线,点击

链接,进入网站进行注册。

添加个性化留言

已为您找到该学者13条结果 成果回收站

上传时间

2005年05月14日

【期刊论文】两段双底物发酵生产1,3-丙二醇

李春, 杨东, 杜晨宇, 张延平, 曹竹安

过程工程学报,2003,3(3),-0001,():

-1年11月30日

摘要

利用Klebsiella pneumoniae生长与催化耦合的特点,将好氧生长与厌氧转化两个过程耦合,开发了两段双底物发酵生产1,3-丙二醇的新工艺,并对其工艺特点进行了初步研究。结果表明,采用两段双底物发酵工艺,发酵过程菌体浓度明显高于传统的厌氧转化工艺,OD650最大值达到9.37,发酵60h,1,3-丙二醇的浓度达到50.16g/L,生成速率达0.836g/(L×h),比传统工艺提高了45%。

Klebsiella pneumoniae, 1,, 3-丙二醇, 甘油, 两段双底物发酵

上传时间

2005年05月14日

【期刊论文】工业生物催化过程的发展及其展望

李春, 杜晨宇, 张木, 曹竹安

化工学报,2003,54(4):456~463,-0001,():

-1年11月30日

摘要

综述了近年来工业生物催化过程的发展,提出按照生物催化剂的制备和催化过程的特点将工业生物催化分成生长耦联型催化和生长非耦联型催化,通过这两类生物催化成功的范例以及研究进展讨论生物催化工业化的途径和方法及进一步发展的方向和对策。

生物催化剂 催化过程 生长耦联型 生长非耦联型

上传时间

2005年05月14日

【期刊论文】Intracellular pH and Metabolic Activity of Long-Chain Dicarboxylic Acid-Producing Yeast Candida tropicalis

李春, SHUCHEN LIU, , * CHUN LI, LANGYI XIE, AND ZHU'AN CAO

JOURNAL OF BIOSCIENCE AND BIOENGINEERING Vol. 96, No.4, 349-353. 2003,-0001,():

-1年11月30日

摘要

The intracellular pH (pHi) of a,dicarboxylic acid producing Candida tropicalis was determined by a fluorescence technique using the pH-sensitive fluorescent probe 5(6)-carboxyfluorescein diacetate. Fermentations with n-tridecane substrate to produce a,-tridecanedioic acid were carried out in a 5-l bioreactor in which growth and production were separated. During the growth phase, the measured pHi values were varied from 5.65 to 6.15 in all the experiments performed under different constant pH-operating conditions. The specific rates of growth, sucrose consumption, CO2 production, and O2 consumption were correlated with pHi. Cytochrome P450 monooxygenase (P450), which catalyzes n-alkane hydroxylation, was only slightly expressed during the growth phase. During the first 6h of the production phase, P450 activity was induced rapidly accompanying higher pHi. A much higher level of P450 activity was observed at pHi of 6.55

intracellular pH,, Candida tropicalis,, tridecanedioic acid,, metabolic activity,, P450]

上传时间

2005年05月14日

【期刊论文】发酵液的组成对纳滤分离谷氨酰胺的影响

李春, 刘元帅, 李书良, 王晓琳, 曹竹安

过程工程学报,2003,3(2),-0001,():

-1年11月30日

摘要

研究了谷氨酰胺发酵液中盐离子对纳滤分离提取谷氨酰铵的作用,系统地考察了操作温度和发酵液组成对纳滤分离透过特性的影响,确定了纳滤分离时发酵液最佳稀释倍数和操作温度。结果表明,二价阳离子通过改变膜面电荷密度对谷氨酸的透过特性产生很大影响,使其截留率降低了8%。发酵液中较高浓度的(NH4)2SO4使谷氨酸和谷氨酰胺的截留率和透过通量明显降低,但较高浓度的NH4Cl影响较小,这体现了纳滤膜对不同离子排斥力的差异。当发酵液稀释至谷氨酰胺浓度为1%,pH调至7时,发酵液中的其它盐离子和残糖因浓度较低而对纳滤分离影响不显著。

发酵液, 谷氨酰胺, 纳滤分离, 盐离子

上传时间

2005年05月14日

【期刊论文】A model for signal transduction in suspension cultures of Taxus chinensis var. mairei induced by an oligosaccharide from Fusarium oxysporum

李春, Ying-Jin Yuan*, Chun Li, Jin-Chuan Wu & Zong-Ding Hu

Biotechnology Letters 24: 407~412, 2002.,-0001,():

-1年11月30日

摘要

A non-linear cascade model is proposed to describe the signal transduction pathway in suspension cultures of Taxus chinensis var. mairei induced by an oligosaccharide from Fusarium oxysporum. The oxidative burst intensity, which was defined as the amount of the free radicals including superoxide anion (O2·), H2O2 and OH− and measured by ESR spectrometry, was used as the signal characteristic and the theory of electronic signal transduction cascade was then applied to derive the initial model. The model shows that the signal transduction cascade process is composed of three cascade nets, represented by the phosphorylation of a G-protein, activation of an ion channel and phospholipase C, and phosphorylation of protein kinase C. The three reactions were calculated as beginning at 30.5, 48.8 and 141.4min after elicitation, and the maximum variation rates of the signal intensity in the three nets occurred at 43.2, 80.6 and 192.6min, respectively. The validity of the model predictions was verified by experimental data.

oligosaccharide,, signal transduction,, suspension culture,, Taxol,, Taxus chinensis var., mairei

合作学者

  • 李春 邀请

    石河子大学,新疆

    尚未开通主页